Tlic. Culaiu'ous (jlaiuls of ('oiiiinoii Toads. 327 



of six or eight pairs (Fig. 9). The first occurs over the eye bulges, 

 a second and third close to either end of the parotids. Others are 

 present on back to near the tip of the vertebral column. There 

 exists no uniformity between the shape and size of the spots which 

 occupy a somewhat corresponding position. On either side of the 

 median line of the same individual, an approximately equal area 

 is occupied by spots, even though their number may not be equal. 

 Some animals possess small and numerous spots, others fewer but 

 larger ones. Spots which appear as a continuous band across the 

 legs when they are folded against the body occur with considerable 

 constancy over the thigh and tibular portion of the hind limbs. 

 Darker bands are also present over the cheeks and ulnar portion 

 of the fore limbs. Minor, less distinct spots are found on the remain- 

 ing dorsal surface of the flanks and limbs. 



Eolation of warts to spots. The parotids are, as a rule, of the 

 same or of a slightly darker shade than the ground color of the dorsal 

 surface. Only occasionally is one or both of these warts covered 

 by a decided spot. Quite often, however, the darker pigment spreads 

 very faintly over a part of the surface. Far the greater majority 

 of warts forming the second class [(2) p. 325] are grouped in those 

 spot areas of the dorsal surface, which are most decided in color and 

 in the dark band across the tibular portion of the legs. The warts 

 are of a lighter shade than the spots and this fact further increases 

 the complexity of the color pattern. 



Except for the one or two days of each year spent in the water, 

 at the breeding season, the toad passes its time on, or burrowing into 

 dry land and to this end its outer covering is adapted. The smooth 

 slimy skin of the tadpole, during metamorphosis and growth into 

 the adult, gives place to a relatively dry and extremely warty skin. 

 This admirably fits the toad, even aside from its characteristic colora- 

 tion, to harmonize with the loose soil of the garden or road side. 



The Epidermis. 

 Strata. The lower layer of cells, those in contact with the cutis, 

 constitute the germinating stratum. As the cells pass outward from 

 this stratum, they show a gradual change in their shape and character. 



